Melatonin supplementation during controlled ovarian stimulation for women undergoing assisted reproductive technology: systematic review and meta-analysis of randomized controlled trials

The Effect of Nutrient Supplementation on Female Fertility: A Systematic Review

Assisted reproductive technologies (ART) have improved infertility treatment but reproductive outcomes remain challenging. Nutrient supplementation is being explored to enhance pregnancy rates, increase live birth rates, and reduce miscarriage rates in females undergoing ART. Nutrients like folic acid, omega-3 fatty acids, and antioxidants have shown potential benefits, yet conflicting results exist. Live birth rates may also be influenced by nutrient supplementation, with coenzyme Q10 and vitamin D showing promise. Miscarriage rates may be reduced with nutrients such as vitamin D, omega-3 fatty acids, and antioxidants, although more research is needed for definitive conclusions. Scientific and medical literature databases such as Cochrane Library, PubMed, and Web of Science were queried to identify relevant English publications adhering to predetermined inclusion and exclusion criteria. Various reproductive metrics, encompassing biochemical pregnancy rate, clinical pregnancy rate, ongoing pregnancy rate, implantation rate, live birth rates, and miscarriage rates, were assessed as clinical endpoints. The study population included 996 female subjects receiving ART. Two studies performed investigations on subjects diagnosed with unexplained infertility, two studies specifically included polycystic ovary syndrome patients, and five studies did not provide any specific information on the type of infertility or subfertility. All studies reported on the clinical/ongoing pregnancy rate, among which four included studies observed a significantly higher rate. Out of the four studies that reported on implantation rates, three found significantly higher rates in treatment groups. Out of the three studies that reported on biochemical pregnancy rates, two studies found significantly higher rates in treatment groups. With respect to the clinical outcomes that were studied in this analysis, variable effects of nutritional supplementation on reproductive parameters were observed. Some studies reported significantly higher rates of clinical/ongoing pregnancy, implantation, biochemical pregnancy, and live birth, while no significant difference was found in miscarriage rates.

Letrozole cotreatment progestin-primed ovarian stimulation in women undergoing controlled ovarian stimulation for in vitro fertilization

AIM

To investigate the impact of letrozole cotreatment progestin-primed ovarian stimulation (PPOS) (Le PPOS) in controlled ovarian stimulation (COS) and the pregnancy outcomes in frozen-thawed embryo transfer cycles.

METHODS

This retrospective cohort study included women who underwent in vitro fertilization (IVF)/intracytoplasmic sperm injection (ICSI). A total of 2575 cycles were included (1675 in the Le PPOS group and 900 in the PPOS group). The primary outcome was the clinical pregnancy rates. The secondary outcome was the live birth rates.

RESULTS

In this study, propensity score matching (PSM) was performed to create a perfect match of 379 patients in each group. After matching, the numbers of oocytes retrieved, mature oocytes, fertilization, and clinical pregnancy rates were more favorable in the Le PPOS group than in the PPOS group (all p < 0.05). The multivariable analysis showed that the clinical pregnancy rate was higher in the Le PPOS than in the PPOS group (odds ratio = 1.46, 95% confidence interval: 1.05-2.04, p = 0.024) after adjusting for potentially confounding factors (age, anti-Müllerian hormone levels, antral follicular count, the type of embryo transferred, number of transferred embryos, body mass index, and follicular stimulating hormone and estradiol levels on starting day).

CONCLUSIONS

This retrospective study with a limited sample size suggests that the Le PPOS protocol might be an alternative to the PPOS protocol in women undergoing COS and could lead to better pregnancy outcomes. The results should be confirmed using a formal randomized controlled trial.

Melatonin and its Emerging Physiological Role in Reproduction: A Review and Update

Melatonin is a neuroendocrine hormone secreted by the pineal gland. The secretion of melatonin follows a circadian rhythm controlled by the suprachiasmatic nucleus, and its secretion is synchronized with the changes in light and dark periods in nature, with the highest secretion level at night. Melatonin is a critical hormone that coordinates external light stimulation and cellular responses of the body. It transmits information about the environmental light cycle, including the circadian and seasonal rhythms, to the relevant tissues and organs in the body, which, along with changes in its secretion level, ensures that its regulated functional activities are adapted in response to changes in the outside environment. Melatonin takes beneficial actions mainly through the interaction with specific membrane-bound receptors, termed MT1 and MT2. Melatonin also acts as a scavenger of free radicals via non-receptor-mediated mechanism. For more than half of acentury melatonin has been associated with vertebrate reproduction, especially in the context of seasonal breeding. Though modern humans show little remaining reproductive seasonality, the relationships between melatonin and human reproduction continue to attract extensive attention. Melatonin plays important roles in improving mitochondrial function, reducing the damage of free radicals, inducing oocyte maturation, increasing fertilization rate and promoting embryonic development, which improves the outcomes of in vitro fertilization and embryo transfer. The present article reviews the progress that has been made in our evolving understanding of the physiological role of melatonin in reproduction and its potential clinical applications in reproductive medicine.

Interventions to prevent or reduce the incidence and severity of ovarian hyperstimulation syndrome: a systematic umbrella review of the best clinical evidence

Ovarian hyperstimulation syndrome (OHSS) is a potentially life-threating iatrogenic complication of the early luteal phase and/or early pregnancy after in vitro fertilization (IVF) treatment. The aim of the current study was to identify the most effective methods for preventing of and reducing the incidence and severity of OHSS in IVF patients. A systematic review of systematic reviews of randomized controlled trials (RCTs) with meta-analysis was used to assess each potential intervention (PROSPERO website, CRD 268626) and only studies with the highest quality were included in the qualitative analysis. Primary outcomes included prevention and reduction of OHSS incidence and severity. Secondary outcomes were maternal death, incidence of hospital admission, days of hospitalization, and reproductive outcomes, such as incidence of live-births, clinical pregnancies, pregnancy rate, ongoing pregnancy, miscarriages, and oocytes retrieved. A total of specific interventions related to OHSS were analyzed in 28 systematic reviews of RCTs with meta-analyses. The quality assessment of the included studies was high, moderate, and low for 23, 2, and 3 studies, respectively. The certainty of evidence (CoE) for interventions was reported for 37 specific situations/populations and resulted high, moderate, and low-to-very low for one, 5, and 26 cases, respectively, while it was not reported in 5 cases. Considering the effective interventions without deleterious reproductive effects, GnRH-ant co-treatment (36 RCTs; OR 0.61, 95% C 0.51 to 0.72, n = 7,944; I² = 31%) and GnRH agonist triggering (8 RCTs; OR 0.15, 95% CI 0.05 to 0.47, n = 989; I² = 42%) emerged as the most effective interventions for preventing OHSS with a moderate CoE, even though elective embryo cryopreservation exhibited a low CoE. Furthermore, the use of mild ovarian stimulation (9 RCTs; RR 0.26, CI 0.14 to 0.49, n = 1,925; I² = 0%), and dopaminergic agonists (10 RCTs; OR 0.32, 95% CI 0.23 to 0.44, n = 1,202; I² = 13%) coadministration proved effective and safe with a moderate CoE. In conclusion, the current study demonstrates that only a few interventions currently can be considered effective to reduce the incidence of OHSS and its severity with high/moderate CoE despite the numerous published studies on the topic. Further well-designed RCTs are needed, particularly for GnRH-a down-regulated IVF cycles.

Effects of exogenous melatonin supplementation on health outcomes: An umbrella review of meta-analyses based on randomized controlled trials

Various melatonin supplementations have been developed to improve health outcomes in various clinical conditions. Thus, we sought to evaluate and summarize the effect of melatonin treatments in clinical settings for health outcomes. We searched PubMed/Medline, Embase, and Cochrane Library from inception to 4 February 2021. We included meta-analyses of randomized controlled trials investigating the melatonin intervention for any health outcome. Based on the different effect sizes of each meta-analysis, we calculated random models' standardized mean differences or risk ratios. We observed robust evidence supported by statistical significance with non-considerable heterogeneity between studies for sleep-related problems, cancer, surgical patients, and pregnant women. Patients with sleep disorder, sleep onset latency (SMD 0.33, 95% CI: 0.10 - 0.56, P < 0.01) were significantly improved whereas no clear evidence was shown with sleep efficiency (1.10, 95% CI: -0.26 to 2.45). The first analgesic requirement time (SMD 5.81, 95% CI: 2.57-9.05, P < 0.001) of surgical patients was distinctly improved. Female patients under artificial reproductive technologies had significant increase in the top-quality embryos (SMD 0.53, 95% CI: 0.27 - 0.79, P < 0.001), but no statistically clear evidence was found in the live birth rate (SMD 1.20, 95% CI: 0.83 - 1.72). Survival at one year (RR 1.90, 95% CI: 1.28 - 2.83, P < 0.005) significantly increased with cancer patients. Research on melatonin interventions to treat clinical symptoms and sleep problems among diverse health conditions was identified and provided considerable evidence. Future well-designed randomized clinical trials of high quality and subgroup quantitative analyses are essential.

Oral melatonin supplementation during in vitro fertilization treatment: a systematic PRISMA review and meta-analysis of randomized controlled trials

OBJECTIVE

High levels of reactive oxygen species (ROS) have been suspected of reducing the success rate of assisted reproductive technology (ART). Melatonin has anti-oxidative properties and could therefore be of interest as a supplement in in vitro-fertilization (IVF) protocols. The objective of this study was to evaluate if a melatonin supplementation given in vivo to women undergoing IVF-treatment can improve the outcome.

METHODS

A systematic literature search was performed on PubMed, Embase and Cochrane. The methodological quality of the included studies was assessed using the version 2 of the Cochrane risk-of-bias tool (RoB2). Primary outcome was clinical pregnancy rate (CPR). Secondary outcomes were total number of oocytes, number of mature oocytes, embryo quality, biochemical pregnancy rate, miscarriage rate and live birth rate (LBR).

RESULTS

Seven randomized controlled trials (RCT) were included. The meta-analysis demonstrated a significantly higher mature oocyte count when melatonin was used (Mean Diff. = 1,82; 95% CI 0.37-3.27; p = .01). All seven studies showed a trend for increase in CPR, although not significant. No other measured outcomes showed a significant improvement. Two studies had 'low risk', three 'some concerns' and two studies had 'high risk' of bias.

CONCLUSION

This meta-analysis including RCT indicates that an oral melatonin supplement during IVF-treatment can increase the number of mature oocytes, and a trend for increase CPR, albeit not significant. Most of the included studies were small. The methodological quality in three of the seven studies was moderate and two were low. Further investigations are needed to support the positive findings.

Effects of Supplementation with Natural Antioxidants on Oocytes and Preimplantation Embryos

For most infertile couples, in vitro fertilization (IVF) represents the only chance to conceive. Given the limited success of IVF procedures, novel approaches are continuously tested with the aim of improving IVF outcomes. Growing attention is devoted today to the potential benefit of natural antioxidants in the optimization of infertility treatments. This review summarizes current data in this context, focusing on both experimental studies on oocytes/embryos and clinical trials on antioxidants supplementation. Based on information gained from experimental studies, antioxidant supplementation may have beneficial effects on IVF outcomes in terms of quality and cryotolerance of in vitro produced embryos, together with positive effects on in vitro maturation oocytes and on early embryonic development. Unfortunately, from the clinical side, there is a paucity of evidence favoring the protective qualities of antioxidants. Among the antioxidants considered, coenzyme Q10 may be regarded as one of the most promising for its positive role in rescuing the oxidative stress-induced damages, but further data are needed. It is concluded that further trials are necessary to characterize the potential clinical value of antioxidants in IVF treatments.

Redox Biology of Human Cumulus Cells: Basic Concepts, Impact on Oocyte Quality, and Potential Clinical Use

Significance: Four decades have passed since the first successful human embryo conceived from a fertilization in vitro. Despite all advances, success rates in assisted reproduction techniques still remain unsatisfactory and it is well established that oxidative stress can be one of the major factors causing failure in in vitro fertilization (IVF) techniques. Recent Advances: In the past years, researchers have been shown details of the supportive role CCs play along oocyte maturation, development, and fertilization processes. Regarding redox metabolism, it is now evident that the synergism between gamete and somatic CCs is fundamental to further support a healthy embryo, since the oocyte lacks several defense mechanisms that are provided by the CCs. Critical Issues: There are many sources of reactive oxygen species (ROS) in the female reproductive tract in vivo that can be exacerbated (or aggravated) by pathological features. While an imbalance between ROS and antioxidants can result in oxidative damage, physiological levels of ROS are essential for oocyte maturation, ovulation, and early embryonic growth where they act as signaling molecules. At the event of an assisted reproduction procedure, the cumulus/oophorus complex is exposed to additional sources of oxidative stress in vitro. The cumulus cells (CCs) play essential roles in protecting the oocytes from oxidative damage. Future Directions: More studies are needed to elucidate redox biology in human CCs and oocyte. Also, randomized controlled trials will identify possible benefits of in vivo or in vitro administration of antioxidants for patients seeking IVF procedure.

Melatonin Application in Assisted Reproductive Technology: A Systematic Review and Meta-Analysis of Randomized Trials

Objective: To study whether melatonin treatment can increase clinical pregnancy rate and live birth rate in assisted reproductive technology (ART) cycles. Methods: Literature searches were conducted to retrieve randomized trials that reported the effect of melatonin treatment on ART outcomes. Databases searched included PubMed, EMBASE, Cochrane Library, Web of Science, and Google Scholar. Results: Ten studies matched the inclusion criteria. Clinical pregnancy was reported in all of the included studies and live birth was reported in three studies. Melatonin treatment significantly increased the clinical pregnancy rate [OR = 1.43 (1.11, 1.86), power = 0.98, 10 RCTs, low-quality evidence] but not the live birth rate [OR = 1.38 (0.78, 2.46), power = 0.34, 3 RCTs, low-quality evidence]. Melatonin treatment increased the number of oocyte collected [SMD = 0.34 (0.01, 0.67), 7 RCTs, low-quality evidence], the number of maturated oocyte [SMD = 0.56 (0.27, 0.85), 7 RCTs, low-quality evidence], and the number of good quality embryo [MD = 0.36 (0.18, 0.55), 3 RCTs, low-quality evidence]. Melatonin treatment significantly increased the biochemical pregnancy rate [OR = 1.65 (1.14, 2.38), 6 RCTs, low-quality evidence] and had no significant effect on the miscarriage rate [OR = 1.28 (0.65, 2.51), 5 RCTs, low-quality evidence]. Conclusion: Melatonin treatment significantly increases the clinical pregnancy rate but not live birth rate in ART cycles. Melatonin treatment also increases the number of oocyte collected, maturated oocyte, and good quality embryo. No clear evidence suggested that melatonin treatment increased the adverse events in ART cycles. The actual findings may be compromised due to the wide heterogeneity of the included IVF patients, from PCOS to low ovarian reserve.

Observation of Parthanatos Involvement in Diminished Ovarian Reserve Patients and Melatonin's Protective Function Through Inhibiting ADP-Ribose (PAR) Expression and Preventing AIF Translocation into the Nucleus

Diminished ovarian reserve (DOR) is characterized by the depletion of the ovarian pool, which leads to reductions in oocyte quality and quantity. Studies have suggested that ovarian reserve or ovarian aging is tightly related to apoptosis. However, the cell death mechanism is not comprehensively understood. Parthanatos, a type of poly [ADP-ribose] polymerase 1(PARP1)-dependent and apoptosis-inducing factor (AIF)-mediated cell death, plays a crucial role in various disorders. In the present study, we aimed to investigate whether parthanatos is involved in the pathogenesis of DOR. We recruited 40 patients (20 DOR patients and 20 normal ovarian reserve (NOR) patients) and examined PAR expression and AIF translocation in their isolated cumulus GCs (granulosa cells) by fluorescence microscopy. Our results demonstrated that PAR expression and AIF nuclear translocation were significantly higher in cumulus GCs of DOR patients, suggesting that PARP1-dependent cell death may be associated with DOR pathophysiology. Moreover, we tested the protective function of melatonin on hydrogen peroxide (H₂O₂)-induced parthanatos in human ovarian cancer (IGROV1) cells. Our results demonstrated that H₂O₂ treatment of IGROV1 cells led to excessive protein PARylation and AIF translocation into the nuclei. Melatonin effectively inhibits PARylation, blocks translocation of AIF into the nucleus, and consequently decreases the risk of parthanatos in cumulus GCs.

Effects of Melatonin Administration on Chemical Pregnancy Rates of Polycystic Ovary Syndrome Patients Undergoing Intrauterine Insemination: A Randomized Clinical Trial

Background

Oxidative stress as a potential cause of poor oocyte quality can influence a female's reproductive system. This study aimed to investigate the effects of melatonin on chemical pregnancy rates of a significant number of polycystic ovary syndrome (PCOS) patients undergoing intrauterine insemination (IUI).

Materials and Methods

In this double-blinded randomized clinical trial (RCT) study, the samples included 198 PCOS patients fulfilling the inclusion criteria and undergoing the IUI treatment. On the third day of menstruation, a 3-mg melatonin tablet or its placebo was given to the patients according to the randomized study protocol; this prescription was continued until the day of human chorionic gonadotropin (hCG) administration. The current study attempted primarily to scrutinize the effect of melatonin administration on the rate of chemical pregnancy and mature follicles during the IUI treatment cycle, and secondarily to determine the endometrial thickness (ET) on the day of IUI.

Results

The mean age of the participants in the study was 28.9 ± 5.5 years. The chemical pregnancy rate in the group receiving melatonin was about 32%, when it was 18% in the control group (P=0.012). Furthermore, it was concluded that the addition of melatonin to the treatment cycle of PCOS individuals could significantly improve the ET after the treatment (P<0.001).

Conclusion

The results of this study demonstrated that the treatment of PCOS patients undergoing IUI with melatonin significantly improves the rate of chemical pregnancy (Registration number: IRCT2017021132489N1).

Melatonin and health: an umbrella review of health outcomes and biological mechanisms of action

BACKGROUND

Our aims were to evaluate critically the evidence from systematic reviews as well as narrative reviews of the effects of melatonin (MLT) on health and to identify the potential mechanisms of action involved.

METHODS

An umbrella review of the evidence across systematic reviews and narrative reviews of endogenous and exogenous (supplementation) MLT was undertaken. The Oxman checklist for assessing the methodological quality of the included systematic reviews was utilised. The following databases were searched: MEDLINE, EMBASE, Web of Science, CENTRAL, PsycINFO and CINAHL. In addition, reference lists were screened. We included reviews of the effects of MLT on any type of health-related outcome measure.

RESULTS

Altogether, 195 reviews met the inclusion criteria. Most were of low methodological quality (mean -4.5, standard deviation 6.7). Of those, 164 did not pool the data and were synthesised narratively (qualitatively) whereas the remaining 31 used meta-analytic techniques and were synthesised quantitatively. Seven meta-analyses were significant with P values less than 0.001 under the random-effects model. These pertained to sleep latency, pre-operative anxiety, prevention of agitation and risk of breast cancer.

CONCLUSIONS

There is an abundance of reviews evaluating the effects of exogenous and endogenous MLT on health. In general, MLT has been shown to be associated with a wide variety of health outcomes in clinically and methodologically heterogeneous populations. Many reviews stressed the need for more high-quality randomised clinical trials to reduce the existing uncertainties.

Clomiphene citrate and letrozole to reduce follicle-stimulating hormone consumption during ovarian stimulation: systematic review and meta-analysis

OBJECTIVE

To assess the available evidence comparing effectiveness of ovarian stimulation (OS) using clomiphene citrate (CC) and/or letrozole (LTZ) to reduce follicle-stimulating hormone (FSH) consumption compared with standard OS.

METHODS

We performed a systematic review and meta-analysis of randomized controlled trials that compared reproductive outcomes following in-vitro fertilization. We searched 11 electronic databases and hand-searched the reference lists of included studies and related reviews. We stratified the results, separating studies according to the oral agent used (CC or LTZ) and the characteristics of the included women (expected poor ovarian response or other women). When combining the results of the included studies, we assessed the relative risk (RR) for live birth, clinical pregnancy, miscarriage and cycle cancelation, the Peto odds ratio (OR) for ovarian hyperstimulation syndrome (OHSS) and mean difference (MD) for the number of oocytes retrieved and FSH consumption.

RESULTS

A total of 22 studies were included in the review. Considering women with expected poor ovarian response, the available evidence suggested that using CC to reduce FSH consumption during OS provided similar rates of live birth (RR, 0.9 (95% CI, 0.6-1.2), moderate-quality evidence) and clinical pregnancy (RR, 1.0 (95% CI, 0.8-1.4), moderate-quality evidence); the use of LTZ did not cause a relevant change in the number of oocytes retrieved (MD, -0.4 (95% CI, -0.9 to 0.1), high-quality evidence). Considering the studies evaluating other women, the available evidence suggested that using CC to reduce FSH consumption during OS reduced the number of oocytes retrieved (MD, -4.6 (95% CI, -6.1 to -3.0), high-quality evidence) and risk of OHSS (Peto OR, 0.2 (95% CI, 0.1-0.3), moderate-quality evidence), while results were similar for rates of live birth (RR, 0.9 (95% CI, 0.7-1.1), moderate-quality evidence) and clinical pregnancy (RR, 1.0 (95% CI, 0.8-1.1), high-quality evidence). The quality of the evidence was low or very low for other outcomes.

CONCLUSION

The use of CC to reduce FSH consumption in women with expected poor ovarian response has the advantage of providing similar reproductive outcomes with reduced costs. For the other women, the use of CC for reducing FSH consumption has the additional advantage of reducing OHSS, but also reduces the total number of oocytes retrieved. More studies are needed to evaluate the effect of LTZ for the same purpose. Future studies should focus on cumulative pregnancy per oocyte retrieval, patient dissatisfaction and agreement to repeat the cycle if not pregnant, which are important outcomes for clinical decisions. Copyright © 2017 ISUOG. Published by John Wiley & Sons Ltd.

Oocyte aging underlies female reproductive aging: biological mechanisms and therapeutic strategies

In recent years, postponement of marriage and childbearing in women of reproductive age has led to an increase in the incidence of age-related infertility. The reproductive aging process in women is assumed to occur due to a decrease in both the quantity and quality of the oocytes, with the ultimate result being a decline in fecundity. This age-related decline in fecundity is strongly dependent on oocyte quality, which is critical for fertilization and subsequent embryo development. Aged oocytes display increased chromosomal abnormality and dysfunction of cellular organelles, both of which factor into oocyte quality. In particular, mitochondrial dysfunction has been suggested as a major contributor to the reduction in oocyte quality as well as to chromosomal abnormalities in aged oocytes and embryos. Participation of oxidative stress in the oocyte aging process has been proposed because oxidative stress has the capacity to induce mitochondrial dysfunction and directly damage many intracellular components of the oocytes such as lipids, protein, and DNA. In an attempt to improve mitochondrial function in aged oocytes, several therapeutic strategies have been investigated using both animal models and assisted reproductive technology. Here, we review the biological mechanisms and present status of therapeutic strategies in the female reproductive aging field and indicate possible future therapeutic strategies.

Utility of antioxidants during assisted reproductive techniques: an evidence based review

Assisted reproductive technology (ART) is a common treatment of choice for many couples facing infertility issues, be it due to male or female factor, or idiopathic. Employment of ART techniques, however, come with its own challenges as the in vitro environment is not nearly as ideal as the in vivo environment, where reactive oxygen species (ROS) build-up leading to oxidative stress is kept in check by the endogenous antioxidants system. While physiological amounts of ROS are necessary for normal reproductive function in vivo, in vitro manipulation of gametes and embryos exposes these cells to excessive ROS production either by endogenous or exogenous environmental factors. In this review, we discuss the sources of ROS in an in vitro clinical setting and the influence of oxidative stress on gamete/embryo quality and the outcome of IVF/ICSI. Sources of ROS and different strategies of overcoming the excessive generation of ROS in vitro are also highlighted. Endogenously, the gametes and the developing embryo become sources of ROS. Multiple exogenous factors act as potential sources of ROS, including exposure to visible light, composition of culture media, pH and temperature, oxygen concentration, centrifugation during spermatozoa preparation, ART technique involving handling of gamete/embryo and cryopreservation technique (freeze/thawing process). Finally, the use of antioxidants as agents to minimize ROS generation in the in vitro environment and as oral therapy is highlighted. Both enzymatic and non-enzymatic antioxidants are discussed and the outcome of studies using these antioxidants as oral therapy in the male or female or its use in vitro in media is presented. While results of studies using certain antioxidant agents are promising, the current body of evidence as a whole suggests the need for further well-designed and larger scale randomized controlled studies, as well as research to minimize oxidative stress conditions in the clinical ART setting.

Melatonin: shedding light on infertility?--A review of the recent literature

In recent years, the negative impact of oxidative stress on fertility has become widely recognised. Several studies have demonstrated its negative effect on the number and quality of retrieved oocytes and embryos following in-vitro fertilisation (IVF). Melatonin, a pineal hormone that regulates circadian rhythms, has also been shown to exhibit unique oxygen scavenging abilities. Some studies have suggested a role for melatonin in gamete biology. Clinical studies also suggest that melatonin supplementation in IVF may lead to better pregnancy rates. Here we present a critical review and summary of the current literature and provide suggestions for future well designed clinical trials.

Time-lapse embryo imaging for improving reproductive outcomes: systematic review and meta-analysis

OBJECTIVE

To identify, appraise and summarize the available evidence regarding the effectiveness and safety of time-lapse embryo monitoring on the main outcomes of assisted reproductive techniques.

METHODS

In this systematic review and meta-analysis, we included only randomized controlled trials (RCTs) comparing time-lapse embryo imaging with standard embryo monitoring. Our primary outcomes were live births (efficacy) and congenital abnormalities (safety). The secondary outcomes were clinical pregnancy, ongoing pregnancy and miscarriage.

RESULTS

Two RCTs were considered eligible, and their data were extracted and included in a meta-analysis. In both studies embryos were transferred at the blastocyst stage. No studies reported rates of live birth or congenital abnormalities. Our estimates were not sufficiently precise to identify whether time-lapse monitoring provided a small benefit, no effect or minor harm on rates of clinical pregnancy (relative risk (RR), 1.05 (95% CI, 0.80-1.38)) or ongoing pregnancy (RR, 1.05 (95% CI, 0.76-1.45)), based on two studies involving 138 women with moderate-quality evidence. Considering the available data, we were unable to determine whether the intervention poses substantial benefit, no effect or substantial harm in the risk of miscarriage (RR, 0.95 (95% CI, 0.30-2.99)), based on two studies involving 76 clinical pregnancies with low-quality evidence.

CONCLUSIONS

Time-lapse embryo imaging is unlikely to have a large effect on the chance of achieving clinical and/or ongoing pregnancy when transferring embryos at the blastocyst stage. More studies are required to improve the quality of the current evidence and also to examine whether this intervention is useful when transferring embryos at the cleavage stage.

Melatonin Reverses Fas, E2F-1 and Endoplasmic Reticulum Stress Mediated Apoptosis and Dysregulation of Autophagy Induced by the Herbicide Atrazine in Murine Splenocytes

Exposure to the herbicide Atrazine (ATR) can cause immunotoxicity, apart from other adverse consequences for animal and human health. We aimed at elucidating the apoptotic mechanisms involved in immunotoxicity of ATR and their attenuation by Melatonin (MEL). Young Swiss mice were divided into control, ATR and MEL+ATR groups based on daily (x14) intraperitoneal administration of the vehicle (normal saline), ATR (100 mg/kg body weight) and MEL (20 mg/kg body weight) with ATR. Isolated splenocytes were processed for detection of apoptosis by Annexin V-FITC and TUNEL assays, and endoplasmic reticulum (ER) stress by immunostaining. Key proteins involved in apoptosis, ER stress and autophagy were quantified by immunoblotting. ATR treatment resulted in Fas-mediated activation of caspases 8 and 3 and inactivation of PARP1 which were inhibited significantly by co-treatment with MEL. MEL also attenuated the ATR-induced, p53 independent mitochondrial apoptosis through upregulation of E2F-1 and PUMA and suppression of their downstream target Bax. An excessive ER stress triggered by ATR through overexpression of ATF-6α, spliced XBP-1, CREB-2 and GADD153 signals was reversed by MEL. MEL also reversed the ATR-induced impairment of autophagy which was indicated by a decline in BECN-1, along with significant enhancement in LC3B-II and p62 expressions. Induction of mitochondrial apoptosis, ER stress and autophagy dysregulation provide a new insight into the mechanism of ATR immunotoxicity. The cytoprotective role of MEL, on the other hand, was defined by attenuation of ER stress, Fas-mediated and p53 independent mitochondria-mediated apoptosis as well as autophagy signals.

Impact of endometriosis and its staging on assisted reproduction outcome: systematic review and meta-analysis

OBJECTIVE

To evaluate whether the presence or severity of endometriosis affects the outcome of assisted reproductive techniques (ART).

METHODS

In this systematic review, all studies comparing the outcome of ART in women with and those without endometriosis, or at different stages of the disease, were considered eligible. We used either risk ratio (RR) or mean difference (MD) and their 95%CIs for comparisons. The primary outcome was live birth; the secondary outcome was clinical pregnancy. Miscarriage and the number of oocytes retrieved were examined as additional outcomes.

RESULTS

We included 92 studies in the review and 78 in the meta-analysis: 20,167 women with endometriosis were compared with 121,931 women without endometriosis, and 1703 women with Stage-III/IV endometriosis were compared with 2227 women with Stage-I/II endometriosis. The following results were observed for the comparison of women with endometriosis vs women without endometriosis: live birth, RR = 0.99 (95%CI, 0.92-1.06); clinical pregnancy, RR = 0.95 (95%CI, 0.89-1.02); miscarriage, RR = 1.31 (95%CI, 1.07-1.59); number of oocytes retrieved, MD = -1.56 (95%CI, -2.05 to -1.08). The following results were observed for the comparison of women with Stage-III/IV vs Stage-I/II endometriosis: live birth, RR = 0.94 (95%CI, 0.80-1.11); clinical pregnancy, RR = 0.90 (95%CI, 0.82-1.00); miscarriage, RR = 0.99 (95%CI, 0.73-1.36); number of oocytes retrieved, MD = -1.03 (95%CI, -1.67 to -0.39).

CONCLUSIONS

Women with endometriosis undergoing ART have practically the same chance of achieving clinical pregnancy and live birth as do women with other causes of infertility. No relevant difference was observed in the chance of achieving clinical pregnancy and live birth following ART when comparing Stage-III/IV with Stage-I/II endometriosis. The quality of the evidence for the additional examined outcomes was very low, not allowing meaningful conclusions to be drawn.